Flush anchor snap-off method

ABSTRACT

A method for anchoring one or more tensile members to bone includes: providing an anchor, including: a housing including a body portion and an extension portion interconnected by a breakaway structure which is configured to retain structural integrity under a first predetermined tensile load and to separate under a second predetermined tensile load which is greater than the first predetermined tensile load; a collet disposed in the hollow interior; and a sleeve movable parallel to the central axis between first and second positions; passing one or more tensile members through a central bore of the collet; seating the housing into a bore formed in the bone; and driving the sleeve from the first position towards the second position under the first predetermined tensile load, so as to swage the collet around the one or more tensile members.

BACKGROUND OF THE INVENTION

This invention relates generally to medical implants, and moreparticularly to a method for applying tension along or across a ligamentto repair, augment, or replace it, or applying tension across a bonefracture to reduce it.

Medical implants for tensioning purposes typically comprise one or moretensile members (e.g., sutures or orthopedic cables) connected to one ormore anchors (e.g., suture anchors or suture locks) to create aconverging tensile force between the two anchors. This general concepthas been used in the orthopedic and sports medicine fields to repairtorn or damaged tendons and ligaments, to replace missing or displacedtendons and ligaments, and to anchor grafted or artificial tendons andligaments to bones so that they can grow back together.

Prior art anchor/tensile member configurations typically fall into threefunctional categories; (1) a configuration in which the tensile memberin held in place by an interference fit between the tensile member andbone, (2) a configuration in which the tensile member is tied, glued,melted, or otherwise connected to the anchor during manufacturing orintraoperatively, and (3) a configuration in which the tensile member istensioned or made tight with the use of one of many available andwell-known slip-knots.

It is often desirable to have the ability to tension the configurationprovisionally (i.e. without setting a final irreversible tension) sothat the effect of a particular level of tension can be evaluated andhave the opportunity to “settle in” before it is made permanent.

However, one problem with prior art anchors is that they do notgenerally permit accurate provisional tensioning. When standard sutureanchors are used, the tension is set by estimating the length of thefinal suture implant or tying a slipknot that can be tightened by hand.Some are even tensioned by wrapping the suture around a Kirschner wire(“K-wire”) and twisting the wire to tighten. Even if the initial tensionis estimated well, suture will settle into the soft tissue around it andlose tension after implantation. There does not currently exist a goodway to tension a suture to a known load, “trial” its tension and allowfor some settle in, re-tension, and repeat as needed.

Another problem with prior art suture tensioning techniques is that ofdetermining that excessive tension is our applied. More specifically,because the tension in a suture strand does not exceed its failure loadduring the operative procedure does not mean it will not experience aload greater than its failure load during cyclic loading in-situ.

BRIEF SUMMARY OF THE INVENTION

At least one of these problems are addressed by a modular orthopedicdevice, and implant/instrument system, and method that includes a boneanchor device that is used to secure a tensile member under tension.

According to one aspect of the technology described herein, a method isprovided for anchoring one or more tensile members to bone, including:providing an anchor, including: a housing extending along a central axisbetween open first and second ends, and having a hollow interior, thehousing including a body portion and an extension portion interconnectedby a breakaway structure which is configured to retain structuralintegrity under a first predetermined tensile load and to separate undera second predetermined tensile load which is greater than the firstpredetermined tensile load; a collet disposed in the hollow interior ofthe body portion, the collet having a peripheral wall defining a centralbore for accepting a tensile member therethrough and an exteriorsurface, wherein the collet is configured to be swaged around andagainst the tensile member; a sleeve having a peripheral wall definingopposed interior and exterior surfaces, the sleeve disposed in thehollow interior of the housing and positioned generally axially adjacentto the collet, so as to be movable parallel to the central axis betweenfirst and second positions; and wherein at least one of the exteriorsurface of the collet and the interior surface of the sleeve is taperedand the sleeve and the collet are arranged such that movement of thesleeve from the first position to the second position will cause theinterior surface of the sleeve to bear against the exterior surface ofthe collet, causing the collet to swage radially inwards around andagainst the tensile member; passing one or more tensile members throughthe central bore of the collet; seating the housing into a bore formedin the bone; and driving the sleeve from the first position towards thesecond position under the first predetermined tensile load, so as toswage the collet around the one or more tensile members.

According to another aspect of the technology described herein, a methodis provided for anchoring tensile members to a joint, including:inserting a first tensile member having first and second ends into afirst passage having first and second ends in a first bone; securing thefirst end of the first tensile member in the first end of the firstpassage, using a first anchoring element; inserting a second tensilemember having first and second ends into a second passage having firstand second ends in the first bone; securing the first end of the secondtensile member in the first end of the second passage, using a secondanchoring element; passing the second ends of both first and secondtensile members through a third passage formed in a second bone;providing a third anchoring element, comprising an anchor whichincludes: a housing extending along a central axis between open firstand second ends, and having a hollow interior; a collet disposed in thehollow interior of the housing, the collet having a peripheral walldefining a central bore for accepting a tensile member therethrough andan exterior surface, wherein the collet is configured to be swagedaround and against the tensile members; a sleeve having a peripheralwall defining opposed interior and exterior surfaces, the sleevedisposed in the hollow interior of the housing and positioned generallyaxially adjacent to the collet, so as to be movable parallel to thecentral axis between first and second positions; and wherein at leastone of the exterior surface of the collet and the interior surface ofthe sleeve is tapered and the sleeve and the collet are arranged suchthat movement of the sleeve from the first position towards the secondposition will cause the interior surface of the sleeve to bear againstthe exterior surface of the collet, causing the collet to swage radiallyinwards around and against the tensile members; passing the second endsof the first and second tensile members through the central bore of thecollet; seating the housing into the second bone; applying a first finaltension to the first tensile member; applying a second final tension tothe second tensile member; and driving the sleeve from the firstposition towards the second position, thus swaging the collet around thesecond ends of the first and second tensile members.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be best understood by reference to the followingdescription taken in conjunction with the accompanying drawing figuresin which:

FIG. 1 is a schematic side elevation view of a segment of a prior arttensile member;

FIG. 2 is cross-sectional view of an assembled anchor with a tensilemember engaged therein;

FIG. 3 is an exploded view of the anchor of FIG. 2;

FIG. 4 is a cross-sectional view of FIG. 3;

FIG. 5 is a schematic cross-sectional view of a housing having a flangedisposed at an oblique angle;

FIG. 6 is a schematic side elevation view of a housing having anexterior surface including male threads;

FIG. 7 is a schematic side elevation view of a housing having anexterior surface including a surface coating;

FIG. 8 is a schematic side elevation view of a housing having anexterior surface incorporating knurling;

FIG. 9 is a schematic cross-sectional view of a housing having femalethreads engaging an instrument having male threads;

FIG. 10 is a schematic cross-sectional view of a housing having malethreads engaging an instrument having female threads;

FIGS. 11 and 12 are schematic cross-sectional views of a housing havingbayonet fitting slots engaging bayonet lugs of a correspondinginstrument;

FIGS. 13 and 14 are schematic cross-sectional and top plan views,respectively of a housing having a circumferential slot engaging axiallugs of a corresponding instrument;

FIG. 15 is a schematic cross-sectional view of a housing having acounterbore formed therein engaging collet jaws of a correspondinginstrument;

FIGS. 16 and 17 are schematic side elevation and cross-sectional views,respectively of a housing having a break-away connection to acorresponding instrument;

FIG. 18 is a schematic cross-sectional view of a housing having atapered sleeve retention feature;

FIG. 19 is a schematic cross-sectional view of a housing having a snapring sleeve retention feature;

FIG. 20 is a schematic cross-sectional view of a housing havingresilient sleeve retention tabs;

FIGS. 21 and 22 are schematic cross-sectional and end views,respectively, of a collet having a slotted construction;

FIGS. 23 and 24 are schematic cross-sectional and end views,respectively, of a collet having curvilinear slots formed therein;

FIGS. 25 and 26 are schematic cross-sectional and end views,respectively, of a collet having a spring structure

FIG. 27 is a schematic cross-sectional view of a sleeve having a doubletaper interior surface;

FIG. 28 is a schematic cross-sectional view of a sleeve having a scaledinterior surface;

FIG. 29 is a schematic cross-sectional view of a sleeve having anintegral snap ring interior surface;

FIG. 30 is an exploded view of another exemplary embodiment of ananchor;

FIG. 31 is a cross-sectional view of FIG. 30;

FIG. 32 is a schematic side elevation view of a portion of the anchor ofFIG. 30 in a compressed condition;

FIG. 33 is a cross-sectional view of FIG. 32;

FIG. 34 is a cross-sectional view of the anchor FIG. 30 in an assembledcondition, before compression;

FIG. 35 is a sectional view taken along lines 35-35 of FIG. 34;

FIG. 36 is a cross-sectional view of the anchor FIG. 30 in a compressedcondition;

FIG. 37 is a sectional view taken along lines 37-37 of FIG. 36;

FIG. 38 is a schematic, partially-sectioned perspective view of anexemplary anchor having an integral collet;

FIG. 39 is a schematic, partially-sectioned perspective view of anexemplary anchor having an integral collet and sleeve;

FIG. 40 is a schematic side elevation view of an exemplary housingassembled with a snap-on cap;

FIG. 41 is a sectional view of the housing and cap of FIG. 40;

FIG. 42 is a schematic exploded perspective view of an exemplary housingassembled with a screw-on cap;

FIG. 43 is a sectional view of the housing and cap of FIG. 42;

FIG. 44 is a schematic perspective view of an installation instrumentfor use with the anchor described herein;

FIG. 45 is an exploded view of the installation instrument of FIG. 44;

FIG. 46 is a schematic side elevation view of the installationinstrument of FIG. 44, with a tensioner attached thereto;

FIG. 47 is a schematic cross-sectional view of a distal end of the stemof the installation instrument of FIG. 44, with jaws thereof in an openposition;

FIG. 48 is a view of the stem shown in FIG. 44, with jaws thereof in aclosed position;

FIG. 49 is a schematic cross-sectional view of a distal end of the stemof the installation instrument of FIG. 44, showing an anchor loadedtherein;

FIG. 50 is a view of the stem of FIG. 49, showing a clip in an engagedposition;

FIG. 51 is another view of the stem of FIG. 49, showing a pushrodthereof being actuated;

FIG. 52 is another view of the stem of FIG. 49, showing a clip in areleased position, with the jaws opened to release the anchor;

FIG. 53 is a schematic cross-sectional view of a distal end of a stem ofan alternative installation instrument of, showing an anchor ready to beloaded therein;

FIG. 54 is a view of the stem of FIG. 53, showing an anchor lightlyreceived in jaws of the stem, with a locking sleeve retracted;

FIG. 55 is another view of the stem of FIG. 53, showing a locking sleevepushed down over the jaws to secure the anchor;

FIGS. 56 and 57 are sequential views showing actuation of a pushrod ofthe stem of FIG. 49;

FIG. 58 is another view of the stem of FIG. 49, showing a clip in areleased position, with the jaws opened to release the anchor;

FIG. 59 is a schematic cross-sectional view of an alternative embodimentof an installation instrument stem;

FIG. 60 is a schematic perspective view of an installation instrumenthaving an alternative flexible stem;

FIG. 61 is a schematic view showing the installation instrument of FIG.60 being used in plan an anchor in a human need joint;

FIG. 62 is a schematic perspective view of a button anchor;

FIG. 63 is a schematic perspective view of a suture anchor;

FIG. 64 is a schematic perspective view of an anchor plate;

FIG. 65 is a schematic perspective view of a grommet;

FIG. 66 is a schematic diagram of a tensile member implanted in a humanfemur;

FIG. 67 is a schematic perspective view of a tensile member implanted ina human knee joint;

FIG. 68 is a schematic, partially-sectioned perspective view of anexemplary anchor having an integral internal member;

FIG. 69 is a schematic view showing an arthroscopic procedure in which arigid stem is used to position an anchor in the pelvic region, close tothe superficial surface of the skin;

FIG. 70 is a schematic view showing an arthroscopic procedure in which arigid stem is used to position an anchor in the pelvic region, far fromthe superficial surface of the skin;

FIG. 71 illustrates an arthroscopic procedure in which a rigid stem isused to position an anchor in the knee region, close to the superficialsurface of the skin;

FIG. 72 is a partially cutaway perspective view of an alternativeembodiment of an anchor;

FIG. 73 is a side view of the anchor of FIG. 72;

FIG. 74 is a schematic perspective exploded view of the anchor of FIG.72 in combination with an insertion instrument;

FIG. 75 is a sectioned perspective view of a portion of the anchor ofFIG. 72, showing a breakaway structure thereof;

FIG. 76 is an enlarged view of a portion of FIG. 75;

FIG. 77 is a schematic cross-sectional view of the anchor FIG. 72coupled to an insertion device, prior to a swaging operation;

FIG. 78 is a schematic cross-sectional view of the anchor of FIG. 72,upon completion of a swaging operation;

FIG. 79 is a schematic cross-sectional view of the anchor of FIG. 72,subsequent to completion of a swaging operation, showing an extensionportion of the housing of anchor 72 being separated from the remainderof the anchor;

FIGS. 80-82 are schematic side, and, and enlarged partial sectionalviews, respectively, of a collet having a collapsible construction;

FIGS. 83-85 are schematic side, end, and enlarged partial sectionalviews, respectively, of the collet of FIG. 82, in a collapsed condition;

FIG. 86 is a schematic perspective view an installation instrument, witha first embodiment of a multiple-strand tensioner attached thereto;

FIG. 87 is a schematic perspective view an installation instrument, witha second embodiment of a multiple-strand tensioner attached thereto;

FIG. 88 is a schematic perspective view of a tensile member cuttinginstrument;

FIG. 89 is a cross-sectional view of a portion of the cutting instrumentof FIG. 88 in an open position;

FIG. 90 is a cross-sectional view of a portion of the cutting instrumentof FIG. 88 in a closed position;

FIG. 91 is a cross-sectional view of a portion of an alternative cuttinginstrument in an open position;

FIG. 92 is a cross-sectional view of the cutting instrument of FIG. 91in a closed position;

FIG. 93 is a schematic perspective view of an operating mechanismsuitable for actuating the cutting instrument shown in FIGS. 89-92;

FIG. 94 is a schematic perspective view of an anchor housing includingsuture holes in the flange thereof;

FIG. 95 is a schematic perspective view of an exemplary suture button;

FIG. 96 is a schematic perspective view of another exemplary suturebutton;

FIG. 97 is a schematic diagram showing reduction of a pelvic brimfracture;

FIG. 98 is a schematic diagram showing reduction of a tibial epicondylefracture;

FIG. 99 is a schematic diagram showing reduction of a fibula fracture;

FIG. 100 is a schematic diagram showing tensioning of a rotator cuffagainst the proximal humerus;

FIG. 101 is a schematic diagram showing reduction of a claviclefracture;

FIG. 102 is a schematic diagram showing reduction of a femoralepicondyle fracture;

FIGS. 103A, 103B, and 103C are schematic views of the medial, anterior,and lateral aspects, respectively of a human knee joint, showing asingle strand lateral cruciate ligament augmentation;

FIGS. 104A, 104B, and 104C are schematic views of the medial, anterior,and lateral aspects of a human knee joint, showing a double bundlelateral cruciate ligament augmentation;

FIGS. 105A, 105B, and 105C are schematic views of the medial, interior,and lateral aspects, respectively of a human knee joint, showing asingle strand medial cruciate ligament augmentation;

FIGS. 106A, 106B, and 106C are schematic views of the medial, anterior,and lateral aspects, respectively of a human knee joint, showing adouble bundle medial cruciate ligament augmentation;

FIGS. 107A, 107B, and 107C are schematic views of the medial, anterior,and lateral aspects, respectively of a human knee joint, showing adouble bundle anterior cruciate ligament augmentation;

FIGS. 108A, 108B, and 108C are schematic views of the medial, anterior,and lateral aspects, respectively of a human knee joint, showing adouble bundle posterior cruciate ligament augmentation;

FIGS. 109A and 109B are schematic views of the lateral and medialaspects, respectively of the human foot, showing a double bundleligament augmentation;

FIGS. 110A and 110B are schematic views of the lateral aspect of thehuman foot, showing a single strand forefoot correction;

FIGS. 111A and 111B are schematic views of the medial aspect of thehuman knee joint, in extension and flexion, respectively, and having adouble-bundle ligament augmentation;

FIGS. 112A and 112B are schematic views of the medial aspect of thehuman knee joint, an extension and flexion, respectively and having asingle-strand ligament augmentation;

FIGS. 113 and 114 are schematic side views of the medial aspect of ahuman knee joint showing targets for ligament augmentation drilllocations superimposed thereupon;

FIGS. 115-117 are schematic views of a human knee joint showing a drillguide attached thereto;

FIG. 118 is a schematic side view of a clamp for a cerclage repair;

FIG. 119 is a schematic cross-sectional view of the clamp of FIG. 118;

FIG. 120 is a schematic exploded perspective view of an alternativeclamp for a cerclage repair;

FIG. 121 is a cross-sectional view of the clamp of FIG. 120;

FIG. 122 is a schematic perspective view of the human femur having acerclage applied thereto;

FIG. 123 is a schematic perspective view of a self-tracking reamer;

FIG. 124 is a front elevation view of the self-tracking reamer of FIG.122;

FIG. 125 is a side elevation view of the self-tracking reamer of FIG.122; are schematic views of the medial aspect of the human knee joint,in extension and flexion, respectively, and having a double-bundleligament augmentation;

FIG. 126 is a schematic perspective view of the self-tracking of FIG.122 being used to ream out the canal of a bone;

FIG. 127 is a schematic side elevation view of a flangeless anchorhousing;

FIG. 128 is a cross-sectional view of the anchor housing of FIG. 127;and

FIG. 129 is a schematic view of the anterior aspect of a human kneejoint having a double-bundle ligament augmentation using the anchorhousing shown in FIGS. 127 and 128.

DETAILED DESCRIPTION OF THE INVENTION

In general, the technology described herein provides a modular deviceand implant system and method that enables provisional and permanentlystable tensioning of the tensile member, with minimally-invasive accessto and limited visualization of the bone surface, using a device that issmall and low-profile to prevent stress-shielding and soft tissuehang-up, implanted by simple and intuitive instrumentation thatoptimizes workflow and can be accomplished by one person.

The anchor, installation system, and installation method describedherein are suitable for receiving and securing a tensile member to bone.The term “tensile member” as used herein generally refers to anyflexible element capable of transmitting a tensile force. Nonlimitingexamples of known types of tensile members include sutures andorthopedic cables. FIG. 1 illustrates a short segment of arepresentative tensile member 10 having a diameter “D1”.Commercially-available tensile members intended to be implanted in thehuman body may have a diameter “D1” ranging from tens of microns indiameter to multiple millimeters in diameter. Commercially-availabletensile members may be made from a variety of materials such as polymersor metal alloys. Nonlimiting examples of suitable materials includeabsorbable polymers, nylon, ultrahigh molecular weight polyethylene(“UHMWPE”) or polypropylene titanium alloys, or stainless steel alloys.Known physical configurations of tensile members include monofilament,braided, twisted, woven, and wrapped.

FIG. 2 illustrates an exemplary embodiment of an anchor 12. The anchor12 includes three functional elements, namely a housing 14 configured tobe implanted into bone, a collet 16 received in the housing 14 andconfigured to be swaged around and against a tensile member 10 withoutmoving axially relative to the housing 14 or tensile member 10, and asleeve 18 received in the housing 14 which is capable of moving axiallywithin the housing 14 so as to swage the collet 16, thus retaining thetensile member 10. (Some minimal axial movement of the collet 16 notsignificantly affecting tension may occur during swaging). Each of thesebasic elements is described in detail below with reference to FIGS. 3and 4.

The housing 14 has a body 20 extending along a central axis “A” betweenfirst and second ends 22, 24. The body 20 is defined by a peripheralwall 26 having interior and exterior surfaces 28, 30 respectively, anddefining a hollow interior 29. In the illustrated example, the body 20is generally cylindrical in shape. The first and second ends 22, 24 ofthe body 20 may be chamfered and/or radiused as illustrated or otherwiseshaped to ease insertion into bone. The first end of the body 22 has aninternal flange 31 which is sized to define a stop against axial motionof the collet 16.

A generally annular flange 32 is located at or near the second end 24and extends radially outwards from the body 20. The flange 32 defineslateral and axial surfaces 33, 35 respectively. The size and shape ofthe flange 32 may be selected to suit a particular application. In theexample illustrated in FIG. 4, a reference plane “P” passing through theflange 32 is oriented at an angle θ perpendicular to the central axis A.It will be understood that the orientation of the flange may be variedto suit a particular application. For example, FIG. 5 shows a housing114 in which the angle θ is oblique to the central axis A.

Other means may be provided in order to permit the anchor 12 to beimplanted in various orientations. For example, FIGS. 127 and 128illustrate a housing 5014 which lacks a flange as depicted in otherembodiments. (The housing 5014 may optionally include an extensionportion and breakaway structure as described with respect to otheranchor embodiments, not shown in FIG. 127 or 128). An exterior surface5030 of the body 5020 of the housing 5014 is formed into male threads5034. Alternatively, exterior surface 5030 may be configured (in termsof structure, material selection, or both) according to one of the otherembodiments shown in FIG. 6-8 to improve the connection between thehousing 5014 and the bone. Stated another way, a maximum diameter of thehousing is defined by an outer extent of the threads 5034. The lack ofthe flange extending beyond the outer extent of the threads 5034. Thelack of the flange permits the housing 5014 to be implanted flush orsub-flush relative to the bone surface. More importantly, it permits itto be installed in a bore or passage which is oriented at any arbitraryangle relative to the surface of the bone. In such situations, if aflange were used, a gap would be present between at least some portionsof the flange and the bone. Stated another way, the bore or passage inthe bone can extend along an axis which is oblique to the surface of thebone. An example is shown in FIG. 129 wherein implant having housing5014 is implanted into a human tibia T, in a passage which is oblique tothe surface of the bone.

The anchor 12 may have an overall size which is generally small enoughto be implanted inside a human body. In one example the housing 14 maybe cylindrical in shape with an outside diameter “D2” of about 3 to 12mm, and the flange 32 may have an outside diameter “D3” about 5 to 20mm.

The exterior surface 30 of the housing 14, specifically the body 20 maybe configured (in terms of structure, material selection, or both) toimprove the connection between the housing 14 and the bone. Examples ofexterior surfaces configured to achieve this function are illustrated inFIGS. 6, 7, and 8.

FIG. 6 shows a housing 214 in which an exterior surface 230 of the bodyis formed into male threads 34.

FIG. 7 shows a housing 314 in which an exterior surface 330 of the bodyhas a coating 36 applied thereto which encourages bone growth. Oneexample of a known type of coating that encourages bone growth andinfiltration is an inorganic crystalline structure such ashydroxyapatite (“HA”).

FIG. 8 shows a housing 414 in which an exterior surface 430 of the bodyhas a surface texture 38 incorporating areas which are relatively raisedinterspersed with areas that a relatively lowered. One example of aknown type of surface texture is knurling.

The housing 12 may be provided with means for securing it to bone. Forexample, FIG. 94 illustrates a housing 12 with holes 4030 passingthrough the flange 32. In use, a suture loop (not shown) may be passedaround a bone or other part of a patient's body. Distal ends of thesuture loop may be passed through the holes 4030 and tied together tosecure the housing 12 against the bone surface.

The housing 14 may incorporate a connection feature configured to permita secure, releasable connection to an instrument used for insertion ormanipulation of the anchor 12. Examples of connection features areillustrated in FIGS. 9-17.

FIG. 9 shows a housing 514 incorporating female threads 40 which engagemale threads 42 of an insertion instrument (shown generically at “I”).

FIG. 10 shows a housing 614 having a flange incorporating male threads44 which engage female threads 48 of an insertion instrument I.

FIGS. 11 and 12 show a housing 714 having internal slots 50 whichreceive external lugs 52 formed on the periphery of an insertioninstrument I, forming a “bayonet” type connection.

FIGS. 13 and 14 show a housing 814 having circumferential slots 54formed in the flange 32 which receive cylindrical lugs 55 formed on anend surface of an insertion instrument I.

FIG. 15 shows a housing 914 having a counterbore 56 formed therein sizedto receive collet jaws 58 formed on an insertion instrument I.

FIGS. 16 and 17 show a housing 964 connected to a distal end of aninsertion instrument I by an integral collar 965 which is perforatedwith openings 966. In use, insertion instrument I may be used to implantthe housing 964, and secure the tensile member 10. The collar 965 maythen be fractured in order to detach insertion instrument I. This may bedescribed as a “breakaway” or “snap-off” connection.

The housing 14 may incorporate a sleeve retention feature configured toretain the sleeve 18 in an activated position. These features interactwith retention features of the sleeve 18 which are described in moredetail below. Examples of sleeve retention features are illustrated inFIGS. 18-20.

FIG. 18 shows a housing 1014 incorporating a tapered section 60 in theinterior surface 1028 of the peripheral wall. The tapered section 60 islocated near the first end 1022 of the body 1020.

FIG. 19 shows a housing 1114 in which the interior surface 1128 of theperipheral wall 1126 incorporates a circumferential groove 62 whichreceives a resilient snap ring 64.

FIG. 20 shows a housing 1214 in which the peripheral wall 1226 definesone or more integral resilient locking tabs 66 that extend radiallyinward.

The housing 14 may be made from any material which is biocompatible andwhich will engage the other elements so as to transfer tensile forcethereto. As used herein, the term “biocompatible” refers to a materialwhich is not harmful to living tissue. Nonlimiting examples of suitablematerials for the housing 14 include polymers and metal alloys.Nonlimiting example of suitable metal alloys include stainless steelalloys and titanium alloys. The housing 14 may be fabricated by atechnique such as machining, forging, casting, sintering, or additivemanufacturing (e.g., “3D printing”). Optionally, the housing 14 maycomprise a porous material.

The housing 14 may be treated with known coating such as titaniumnitride, chrome plating, carbon thin films, and/or diamond-like carboncoatings.

The housing 14 may allow for the placement of a cap after implantationto protect the pieces inside or to create a smoother surface. Examplesare shown in FIGS. 40-43.

FIGS. 40 and 41 illustrate a housing 2114 with a flange 2132. A smooth,convex-curved cap 2133 includes an internal recess 2134 closely matchedto the exterior shape of the flange 2132 so that the cap 2133 can engagethe flange 2132 in a snap-fit relationship.

FIGS. 42 and 43 illustrate a housing 2214 with a flange 2232 andinternal threads 2233. A cap 2234 with a smooth, convex-curved exteriorincludes a central stud 2235 with external threads 2236 that can engageinternal threads 2233 to secure the cap 2234 to the housing 2214.

Referring back to FIGS. 3 and 4, the collet 16 is a hollow member withfirst and second ends 67, 68 and an exterior surface 70. The collet 16has a central bore 72 which is sized to receive the tensile member 10described above. For example, the central bore 72 may be cylindrical,with a diameter “D4” which is initially slightly larger than a diameterD1 of the tensile member 10. The central bore 72 need not have acircular cross-section; the cross-section may be a polygon shape (e.g.triangular, square) or it may be a lobed shape (e.g., triangular withradiused corners) or spline shaped.

The collet 16 is configured so as to readily permit it to be swaged,i.e. shaped in such a manner to reduce its cross-section and the size ofthe central bore 72 so that it firmly engages the tensile member 10 andallows a tensile force to be applied thereto. The act of swaging mayinvolve the collet 16 being deformed, crushed, collapsed, or compressed.The collet 16 is configured, e.g., sized and shaped, such that whensubjected to pressure from the sleeve 18, it will abut the internalflange 31 of the body 20, thus stopping its further axial movement, andpermitting the swaging action (described in more detail below) to takeplace without axial movement of the collet 16 relative to the tensilemember 10 or housing 14.

The exterior surface 70 has a shape adapted to interact with theinterior surface of the sleeve 18 described below so as to produce aradially inwardly directed force on the collet 16 in response to theaxial movement of the sleeve 18. Fundamentally, at least one of theexterior surface 70 of the collet 16 and the interior surface of thesleeve 18 incorporates a taper i.e., a diameter or lateral dimensionwhich is larger near the first end and smaller near the second end ofthe respective element. In the example shown in FIGS. 3 and 4, theexterior surface 70 is cylindrical with chamfered ends. FIGS. 21-26generally show alternative collets where the peripheral exterior surfaceis tapered, defining a shape like a frustum of a cone.

Additionally, the internal flange 31 of the housing 14 and the exteriorsurface 70 may be configured such that axial movement of the collet 16towards the first end 22 causes a radially inwardly directed force onthe collet 16. For example, FIG. 4 illustrates a transition section 31′adjacent the interface of the internal flange 31 in the cylindricalportion of the interior surface 28. The shaping of this transitionsection 31′ may be tailored to control the direction and magnitude of aradially-inward force applied to the collet 16. In general, thetransition section defines a constriction adjacent the internal flange31. In the illustrated example, the transition section 31′ is a straighttaper or generally conical section; other shapes such as chamfers,fillets, curves, splines, etc. may be used.

The collet 16 may be made from any material which will engage thetensile member 10 so as to transfer tensile force thereto and which canbe successfully swaged. Nonlimiting examples of suitable materialsinclude polymers and metal alloys. One nonlimiting example of a suitablemetal alloy is an aluminum alloy. The collet 16 may be fabricated by atechnique such as machining, forging, casting, sintering, or additivemanufacturing (e.g., “3D printing”). The collet 16 may be made from amaterial which has a lower effective elastic modulus than the sleeve 18,or stated another way, is “softer” than the sleeve 18. Optionally, thecollet 16 may comprise a porous material.

Optionally, the collet 16 may be coated with a low-friction coating suchas diamond-like carbon (“DLC”).

Optionally, the collet 16 may incorporate a geometry having sections ofremoved material or “negative space” which is configured to facilitatecollapse of the collet 16, so as to optimize stress around the tensilemember 10. Examples of collapsing geometries are illustrated in FIGS.21-26.

FIGS. 21 and 22 show a collet 116 having a longitudinal through slot 74formed on one side, and a longitudinal groove 76 formed opposite thethrough slot 74.

FIGS. 23 and 24 show a collet 216 having a plurality of curvilinearopenings 77 formed through the wall thereof, providing a negative spacethat allows the collet 216 to collapse inwards.

FIGS. 25 and 26 show a collet 316 having a plurality of longitudinalthrough slots 78 formed in the wall thereof, each slot 78 being open toat least one end and extending less than the full length of the collet316. The through slots 78 are arranged to define a spring-likestructure.

Optionally, the collet 16 may incorporate a geometry having sections ofremoved material or “negative space” which are configured to facilitatecollapse of the collet 16, in such a way that portions of the colletprotrude inward into the central bore to provide improved engagementwith a tensile member 10. Examples of collapsing geometries areillustrated in FIGS. 80-85.

FIGS. 80-82 show a collet 3716 having a sidewall 3718 defining a centralbore 3720. It may be made from sintered powdered metal alloy or anothermaterial with similar swaging characteristics. The central bore 3720 mayinclude a surface texture 3721 such as the illustrated threads whichserve to enhance grip on a tensile member 10 (not shown in FIG. 82). Anarray of longitudinal grooves 3722 having a U-shape are formed in theouter surface of the sidewall 3718. Each of the grooves 3722 defines athin neck 3724 (see FIG. 82).

The example shown in FIGS. 80-82 is generally cylindrical prior toswaging. FIGS. 83-85 show the collet 3716 after swaging. Post-swaging,the grooves 3722 may be tapered, having a maximum width at a distal endof the collet 3716, and tapering away to a negligible dimension near amiddle portion of the collet 3716. When swaged as described herein, thesidewall 3718 tends to collapse in a manner such that the neck 3824folds into a U-shape and protrudes into the central bore 3720 (see FIG.85), forming a protrusion 3726 which may have a shape similar to a Romanarch.

Referring back to FIGS. 3 and 4, the sleeve 18 is a hollow member withopen first and second ends 80, 82 The sleeve 18 is sized is such thatthe tensile member 10 described above can pass through the first andsecond ends 80, 82. The sleeve 18 is defined by a peripheral wall 84having interior and exterior surfaces 86, 88, respectively. In theillustrated example, the sleeve 18 is generally cylindrical in shape.

The interior surface 86 has a shape adapted to interact with theexterior surface 70 of the collet 16 described above so as to produce aradially inwardly directed force on the collet 16 in response to theaxial movement of the sleeve 18. As noted above, at least one of theexterior surface 70 of the collet 16 and the interior surface 86 of thesleeve 18 incorporates a taper i.e., a diameter or lateral dimensionwhich is larger near the first end and smaller near the second end ofthe respective element. In the example shown in FIGS. 3 and 4, theinterior surface 86 is tapered, defining a shape like a frustum of acone, with a larger diameter at the first end 80.

The interior surface 86 of the sleeve 18 may have various geometriesselected to optimize the swaging force. The interior surface 86 of thesleeve 18 shown in FIG. 4 has a one-way taper. Examples of alternativecompression surface geometries are illustrated in FIGS. 27-29.

FIG. 27 shows an interior surface 186 with a two-way taper.

FIG. 28 shows an interior surface 286 having a series of step-like facesdefining a “scaled” geometry.

FIG. 29 shows an internal surface 386 with an integral snap ringgeometry.

The sleeve 18 may incorporate a retention feature which cooperates withthe sleeve retention feature of the housing described above in order toretain the sleeve 18 in an activated position. FIG. 4 illustrates anexemplary retention feature in the form of an annular step 90 formed inthe exterior surface 88 of the sleeve 18.

The sleeve 18 may be made from any material which is biocompatible andwhich can receive axial force and transfer radial compressive force tothe collet 16. Nonlimiting examples of suitable materials includepolymers and metal alloys. One nonlimiting example of a suitable metalalloy is a stainless steel alloy. The sleeve 18 may be fabricated by atechnique such as machining, forging, casting, sintering, or additivemanufacturing (e.g., “3D printing”). Optionally, the sleeve 18 maycomprise a porous material.

All or a portion of the sleeve 18 may be provided with a known coatingsuch as titanium nitride, chrome plating, carbon thin films, and/ordiamond-like carbon coatings.

FIGS. 30-37 illustrate another exemplary embodiment of an anchor,denoted 2012 generally. The anchor 2012 is generally similar inconstruction to the anchor 12 described above. Any elements of theanchor 2012 not specifically described may be taken to be identical tothose of the anchor 12. Referring to FIGS. 30 and 31, the anchor 2012includes a housing 2014, a collet 2016 received in the housing 2014, anda sleeve 2018 received in the housing 2014 which is capable of movingaxially within the housing 2014 so as to swage the collet 2016, thusretaining the tensile member 10.

The housing 2014 has a body 2020 extending along a central axis “A”between first and second ends 2022, 2024. The body 2020 is defined by aperipheral wall 2026 having interior and exterior surfaces 2028, 2030respectively, and defining a hollow interior 2029. In the illustratedexample, the body 2020 is generally cylindrical in shape. The first endof the body 2022 has an internal flange 2031 which is sized to define astop against axial motion of the collet 2016.

A generally annular flange 2032 is located at or near the second end2024 and extends radially outwards from the body 2020. In the exampleillustrated in FIGS. 30 and 31, the flange 2032 incorporates chamferedsurfaces 2037 which are configured to engage jaws of an insertioninstrument is described in more detail below.

The exterior surface 2030 of the housing 2014 may be configured toimprove the connection between the housing 2014 and the bone. Examplesof exterior surfaces configured to achieve this function are describedabove and illustrated in FIGS. 6, 7, and 8.

The housing 2014 may incorporate a connection feature configured topermit a secure, releasable connection to an instrument used forinsertion or manipulation of the anchor 2012. Examples of connectionfeatures are described above and illustrated in FIGS. 9-17.

The housing 2014 may incorporate a sleeve retention feature configuredto retain the sleeve 2018 in an activated position. These featuresinteract with retention features of the sleeve 2018 which are describedin more detail below. In the illustrated example, the retention featureis a dimension (e.g., diameter) “D6” of the interior surface 2028 whichis selected to provide a predetermined fit with the sleeve 2018, asdescribed in more detail below.

The collet 2016 is a hollow member with first and second ends 2067, 2068and an exterior surface 2070. The collet 2016 has a central bore 2072which is sized to receive the tensile member 10 described above. Forexample, the central bore 72 may be cylindrical, with a diameter “D5”which is initially slightly larger than a diameter D1 of the tensilemember 10. The central bore 2072 need not have a circular cross-section;the cross-section may be a polygon shape (e.g. triangular, square) or itmay be a lobed shape (e.g., triangular with radiused corners).

The collet 2016 is configured so as to readily permit it to be swaged,i.e. shaped in such a manner to reduce its cross-section and the size ofthe central bore 2072 so that it firmly engages the tensile member 10and allows a tensile force to be applied thereto. The act of swaging mayinvolve the collet 2016 being deformed, crushed, collapsed, orcompressed. The collet 2016 is configured, e.g., sized and shaped, suchthat when subjected to pressure from the sleeve 2018, it will abut theinternal flange 2031 of the body 2020, thus stopping its further axialmovement, and permitting the swaging action to take place without axialmovement of the collet 2016 relative to the tensile member 10 or housing2014.

The exterior surface 2070 has a shape adapted to interact with theinterior surface of the sleeve 2018 described below so as to produce aradially inwardly directed force on the collet 2016 in response to theaxial movement of the sleeve 2018. Fundamentally, at least one of theexterior surface 2070 of the collet 2016 and the interior surface of thesleeve 2018 incorporates a taper i.e., a diameter or lateral dimensionwhich is larger near one end and smaller near the opposite end of therespective element. In the example shown in FIGS. 30 and 31, theexterior surface 2070 is cylindrical with chamfered ends. The exteriordimensions and shape of the exterior surface 2070 are selected so as toprovide a predetermined fit with the sleeve 2018 both before and after acompression process, as described in more detail below.

Additionally, the internal flange 2031 of the housing 2014 and theexterior surface 2070 may be configured such that axial movement of thecollet 2016 towards the first end 2022 causes a radially inwardlydirected force on the collet 16. Examples of this configuration aredescribed above.

The sleeve 2018 is a hollow member with open first and second ends 2080,2082. The sleeve 2018 is sized is such that the tensile member 10described above can pass through the first and second ends 2080, 2082.The sleeve 2018 is defined by a peripheral wall 2084 having interior andexterior surfaces 2086, 2088, respectively. In the illustrated example,the exterior surface 2088 of the sleeve 2018 is generally cylindrical inshape.

The interior surface 2086 has a shape adapted to interact with theexterior surface 2070 of the collet 2016 described above so as toproduce a radially inwardly directed force on the collet 2016 inresponse to the axial movement of the sleeve 2018. As noted above, atleast one of the exterior surface 2070 of the collet 2016 and theinterior surface 2086 of the sleeve 2018 incorporates a taper i.e., adiameter or lateral dimension which is larger near one end and smallernear the opposite end of the respective element. In the example shown inFIGS. 30 and 31, the interior surface 2086 is tapered, defining a shapelike a frustum of a cone, with a larger diameter at the first end 2080.

The interior surface 2086 of the sleeve 2018 may have any of the variousgeometries described above which are selected to optimize the swagingforce.

The sleeve 18 may incorporate a retention feature which cooperates withthe sleeve retention feature of the housing described above in order toretain the sleeve 18 in an activated position. In the illustratedexample, the retention feature is a dimension (e.g., diameter) “D7” ofthe exterior surface 2088 which is selected to provide a predeterminedfit with the sleeve 2018 both before and after a compression process, asdescribed in more detail below.

FIGS. 34-37 illustrate the engineered interference lock feature of theanchor 2012. Referring to FIGS. 34 and 35, in the assembled, butuncompressed condition, there is a small clearance between the insidediameter D6 of the housing 2014 and the outside diameter D7 of thesleeve 2018. There is also a small clearance between the inside diameterD5 of the collet 2016 and the outside diameter D1 of the tensile member10.

FIGS. 36 and 37 illustrate the anchor 2012 in the compressed or actuatedcondition (e.g. after being compressed by one of the insertioninstruments described herein). There is a predetermined interference fitbetween the inside diameter D6 of the housing 2014 and the outsidediameter D7 of the sleeve 2018. This occurs because the sleeve 2018 isforced radially outwards as it is pushed axially over the collet 2016.Furthermore, there is a predetermined interference fit between theinside diameter D5 of the collet 2016 and the outside diameter D1 of thetensile member 10. In this compressed condition, the tensile member 10is significantly compressed radially and held by thehousing-sleeve-collet concentrically compressed configuration.

The materials and/or coatings used in the construction of the housing2014, collet 2016, and sleeve 2018 may be as described for the housing14, collet 16, and sleeve 18 described above.

FIGS. 72-76 illustrate another exemplary embodiment of an anchor,denoted 3012 generally, which incorporates a “breakaway” or “snap-off”connection. The anchor 3012 is generally similar in construction to theanchor 2012 described above. Any elements and/or features of the anchor2012 not specifically described may be taken to be identical to those ofthe anchor 2012. Referring to FIGS. #, the anchor 3012 includes ahousing 3014, a collet 3016 received in the housing 3014, and a sleeve3018 received in the housing 3014 which is capable of moving axiallywithin the housing 3014 so as to swage the collet 3016, thus retainingthe tensile member 10.

The housing 3014 has a body portion 3020 extending along a central axis“A′” between first and second ends 3022, 3024. The portion 3020 isdefined by a peripheral wall 3026 having opposed interior and exteriorsurfaces, and defining a hollow interior. In the illustrated example,the body portion 3020 is generally cylindrical in shape. The first endof the body 3022 has an internal flange 3031 which is sized to define astop against axial motion of the collet 3016.

A generally annular flange 3032 is located at or near the second end2024 and extends radially outwards from the body 2020.

The housing 3014 includes an extension portion 3021 extending away fromthe second end 2024 of the body portion 3020. The extension portion 3021is coupled to the body portion 3020 by a breakaway structure 3023. Asmanufactured and prior to use, the entire housing 3014 forms a singleunitary, integral, or monolithic structure including the body portion3020, extension portion 3021, and breakaway structure 3023.

The extension portion 3021 extends between a first end 3025 and a second3027. The second end 3027 is interconnected to the breakaway structure3023. The first end 3025 may be provided with a connector for beingconnected to an insertion instrument which is described in more detailbelow. In the illustrated example (FIG. 74) the first end 3025 isprovided with a connector 3029 in the form of screw threads.

The breakaway structure 3023 is configured in terms of its shape,dimensions, and material properties such that it will retain itsstructural integrity and interconnected the body portion 3020 and theextension portion 3021 when subjected to tensile loads up to a firstmagnitude sufficient to complete a swaging process of the anchor 3012 asdescribed elsewhere herein. This is referred to herein as a “firstpredetermined tensile load”. The breakaway structure 3023 is furtherconfigured in terms of its shape, dimensions, and material propertiessuch that it will fail and permit separation of the body portion 3020and the extension portion 3021 when subjected to tensile loads equal toor greater than a second magnitude, referred to herein as a “secondpredetermined tensile load”. The second tensile load is greater than thefirst tensile load. The second tensile load may be selected to besufficiently greater than the first predetermined tensile load such thatfailure of the breakaway structure 3023 is unlikely to occur during theswaging process. Stated another way, the second predetermined tensileload may have a safety margin over the first predetermined tensile load.In one example, the second predetermined tensile load may be selected tobe at least 50% to 100% greater than the first predetermined tensileload.

In general, the breakaway structure 3023 may include one or morestress-concentrating columns which present a known cross-sectional area,thus permitting reliable computation of the tensile stresses in thebreakaway structure 3023 for a given applied load.

In the illustrated example, best seen in FIGS. 75 and 76, the breakawaystructure 3023 includes a plurality of stress-concentrating columns 3024arrayed around the periphery of the flange 3032, which have a circularcross-sectional shape adjacent to and/or or at the flange 3032. Thestress-concentrating columns 3024 are separated by openings 3069. Itwill be understood that other column cross-sectional shapes providing apredictable cross-sectional area may be used, and that thecross-sectional shape may vary over the length of the column.

Optionally, the stress-concentrating columns 3024 may intersect theflange 3032 at the bottom of recesses 3033 formed in the flange 3032. Inuse, this permits the stress-concentrating columns 3024 to separatealong the fracture plane which is “below” a top surface 3035, or statedanother way it is sub-flush to, or recessed from, the top surface 3035.

The exterior surface of the housing 2014 may be configured to improvethe connection between the housing 2014 and the bone. Examples ofexterior surfaces configured to achieve this function are describedabove and illustrated in FIGS. 6, 7, and 8.

The housing 3014 and sleeve 3018 may incorporate mutual retentionfeature configured to retain the sleeve 3018 in an activated position,as described above with respect to anchor 2012.

The collet 3016 is a hollow member. The collet 2016 has a central bore2072 which is sized to receive the tensile member 10 described above. Inone example, the collet 3016 may incorporate substantially the samefeatures as collet 2016 described above.

The sleeve 3018 is a hollow member in one example, the sleeve 3018 mayincorporate substantially the same features as sleeve 2018 describedabove.

All or a portion of the anchors described above may be made as part ofan integral, unitary, or monolithic whole. This may be accomplished,example, by using additive manufacturing process.

FIG. 38 illustrates an exemplary anchor 1312 comprising a housing 1314,a collet 1316, and a sleeve 1318 corresponding to those components asdescribed above. In this example, the collet 1316 is integral, unitary,or monolithic with the anchor 1312. The sleeve 1318 is a separatecomponent.

FIG. 39 illustrates an exemplary anchor 1412 comprising a housing 1414which receives an internal member 1416. The internal member 1416 isintegral, unitary, or monolithic with the anchor 1412. This internalmember 1416 is shaped like a tapered coil spring. The bottom end of thecoil spring 1416 is held stationary while the top of the coil spring1416 is allowed to rotate by means of a rotary actuator tool (not shown)that holds the housing 1412 stationary. This tool could be similar to aspanner-type device with pins or lugs and holds the housing 1412stationary by interfacing with the four locking recesses cut into theflange as shown. When the top of the internal member 1416 is rotated (inthis case clockwise), the inner diameter is gradually reduced andconstricts around the tensile member 10 to hold it in place axially.

FIG. 68 illustrates an exemplary anchor 2712 comprising a housing 2714which receives an internal member 2716. This internal member 2716 isshaped like an accordion or wave spring. When compressed axially, thefolds deform, bind together, and swage down on the tensile member 10radially inward. Internal member 2716 thus functions as both a colletand a sleeve. The internal member 2716 optionally may be integral,unitary, or monolithic with the anchor 2712.

FIGS. 44 and 45 an exemplary insertion instrument 1500 which may be usedto insert, tension, and activate the anchors 12 described above. Thebasic components of the insertion instrument 1500 are a body 1502 havinga handle, a stem 1504 extending from the body 1502 and having an anchorconnection mechanism 1508 disposed at a distal end thereof, a hollowpushrod 1510 extending through the stem 1504 and slidably movablebetween retracted and extended positions, and a driving mechanism 1512for moving the pushrod 1510 between retracted and extended positions.The stem 1504 and the pushrod 1510 may be rigid or flexible.

In the illustrated example, the driving mechanism 1512 comprises atoggle linkage 1516 which is manually operated by an operating handle1514. More specifically, the toggle linkage 1516 is arranged such thatwhen the operating handle 1514 is released, return springs 1518 drivethe operating handle 1514, toggle linkage 1518, and pushrod 1510 towardsthe retracted position, and when the operating handle 1514 is squeezed,it moves the toggle linkage 1516 which in turn extends the pushrod 1510towards the extended position. The toggle linkage 1516 may be arrangedto have a fixed or adjustable range of motion.

It will be understood that the driving mechanism 1512 could be replacedwith a different type of mechanical linkage or with the powered devicessuch as an electrical, pneumatic, or hydraulic actuator (not shown).

FIG. 46 illustrates an exemplary tensioner 1520 having a housing 1522which may be connected to the insertion instrument 1500. The tensioner1522 includes a yoke 1524 configured to clamp a tensile member 10passing through the pushrod 1510. The yoke 1524 is movable relative tothe housing 1522, for example using an internal mechanical drivingmechanism (not shown) actuated by an operating knob 1526. Means may beprovided for measuring the tension applied to the tensile member 10. Forexample, the yoke 1524 may be connected to the housing 1522 through acalibrated spring such that the deflection of the yoke 1524 isproportional to applied tension. Alternatively, a calibrated force gaugeor other similar mechanism (not shown) may be provided.

The tensioner 1520 of FIG. 46 is effective to set the tension on asingle tensile member 10. In various applications, which will bedescribed in more detail below, it is desirable to pass multiple tensilemembers 10 through a single anchor, and to set the tension of each ofthe tensile members 10 independently.

FIG. 86 illustrates an exemplary multi-strand tensioner 3920 having ahousing 3922 which may be connected to the any of the insertioninstruments described herein. The housing 3922 includes first and secondsub-housings 3924 Which are arranged in a diverging Y-shape. Eachsub-housing 3924 includes a yoke 3926 configured to clamp a tensilemember 10 passing through the pushrod of the insertion instrument. Eachyoke 3926 is movable relative to its respective sub-housing 3924, forexample using an internal mechanical driving mechanism (not shown)actuated by an operating knob 3928. Means may be provided for measuringthe tension applied to the tensile member 10. For example, the yoke 3926may be connected to the respective sub-housing 3924 through a calibratedspring such that the deflection of the yoke 3926 is proportional toapplied tension. Alternatively, a calibrated force gauge or othersimilar mechanism (not shown) may be provided.

FIG. 87 illustrates another example of a multi-strand tensioner 3930including a housing 3932 including first and second sub-housings 3934arranged in a coaxial configuration. Each sub-housing 3934 includes ayoke 3936 configured to clamp a tensile member 10 passing through thepushrod of the insertion instrument. Each yoke 3936 is movable relativeto its respective sub-housing 3934, for example using an internalmechanical driving mechanism (not shown) actuated by an operating knob3938. Means may be provided for measuring the tension applied to thetensile member 10. For example, the yoke 3936 may be connected to therespective sub-housing 3934 through a calibrated spring such that thedeflection of the yoke 3936 is proportional to applied tension.Alternatively, a calibrated force gauge or other similar mechanism (notshown) may be provided.

An exemplary configuration of the stem 1504 and pushrod 1510 are shownin more detail in FIGS. 47 and 48.

The distal end of the stem 1504 incorporates means for engaging andholding an anchor 12. In the illustrated example, the stem 1504 includesa pair of opposed jaws 1528 with tips 1530, which may be formed asintegral, spring-like extensions of the stem 1504. The tips 1530 may beformed with lateral and axial engagement surfaces 1532, 1534respectively, in order to engage lateral and axial faces, 33, 35respectively of the anchor 12 (shown schematically in FIG. 47). The jaws1528 are provided with axially-extending hooks 1536 which are set backfrom the tips 1530. A clip 1538 having a U-shape with axially-extendinglegs 1540 is disposed laterally between the jaws, in an axial positionwhich is between the tips 1530 and the hooks 1536. The clip 1538 mayhave an opening 1542 passing therethrough, and the pushrod 1510 may bestepped, having a first portion at its distal end small enough to passthrough the opening 1542, and a second portion sufficiently larger toengage the clip 1538.

FIG. 47 shows the stem 1504 with the pushrod 1510 in a fully extendedposition, pushing the clip 1538 outwards and spreading the jaws 1528apart so as to release the anchor 12. FIG. 48 shows the stem 1504 withthe pushrod 1510 in a retracted position, allowing the clip 1538 to moveinwards, engaging the hooks 1536, thereby pulling the jaws inwards sothe tips 1530 engage the flange 32 of the anchor 12. In this position,the anchor 12 is securely held by the stem 1504 and may be manipulatedas necessary. The clip 1538 secures the jaws 1528 in the closed positionuntil such time as the pushrod 1510 is actuated, thus disengaging theclip in the jaws as shown in FIG. 33.

FIGS. 49-52 show the sequence of operation of the insertion instrument1500. FIG. 49 shows an anchor 12 received in the jaws 1528, with theclip 1538 is in a released position. FIG. 50 shows the clip 1538 in anengaged position, holding the jaws 1528 closed. The clip 1538 may beengaged manually, or may be pressed against a tool or fixture (notshown) in order to engage it. FIG. 51 shows the pushrod 1510 beingactuated to press the sleeve 18 down over the collet 16. FIG. 52 showsthe clip 1538 moved to the released position by the pushrod 1510, andthe jaws 1528 open so that the insertion instrument can be removed.

FIGS. 53-58 illustrate an alternative stem 2504 and a method of itsoperation. The distal end of the stem 2504 includes pair of opposed jaws2528 with tips 2530, which may be formed as integral, spring-likeextensions of the stem 2504. The jaws 2528 flank a pushrod 2510substantially similar to pushrod 1510 described above. The tips 1530 maybe formed with V-shaped engagement surfaces 2532 in order to engage ananchor 12. The V-shaped engagement surfaces 2532 are especially suitablefor engaging the chamfered surfaces 2037 of the flange 2032 of theanchor 2012. A generally tubular lock sleeve 2538 having conical endface 2540 surrounds the stem 2504.

FIGS. 53-58 show the sequence of operation of the alternative stem 2504.FIG. 53 shows the lock sleeve 2538 retracted from the jaws 2528. Ananchor 2012 is ready to be picked up by the jaws 2538. The anchor 2012may be held in this position by suitable packaging (not shown).

FIG. 54 shows the jaws 2538 sprung over top of and lightly engaging theflange 2032 of the anchor 2012 with spring pressure.

FIG. 55 shows the lock sleeve 2538 axially slid over the jaws 2538,applying radially inward compressive pressure to the jaws and securelyretaining the anchor 2012.

FIGS. 56-57 shows successive stages of actuation of the pushrod to crimpa tensile member 10 in the anchor 2012, substantially as describedabove.

Three. 58 shows the lock sleeve 2538 retracted from the jaws 2538,allowing the stem 2504 two be detached from the anchor 2012.

FIG. 59 illustrates another alternative stem 1604. It includes malethreads 1646 formed on a distal end which engage female threads formedon anchor housing 14. It also includes an axially-facing shoulder 1648.When fully threaded onto the stem 1604, the flange 32 of the housing 14abuts the shoulder 1646. This construction provides a highly rigidinterconnection between the housing 14 and the stem 1604 in order tomaximize the surgeon's control and ability to manipulate the anchor 12.The hollow pushrod 1610 is mounted inside the stem and operates like thepushrod 1510 described above in order to swage the collet 16 whendesired.

FIGS. 74 and 77-79 illustrate another alternative insertion instrument3500 which may be used to insert, tension, and activate the anchors 12described above. The insertion instrument 3500 is particularly suitablefor use with the breakaway or snap-off anchor 3012 as shown in FIGS.72-76. The basic components of the insertion instrument 3500 are a body3502 having a handle, a hollow pushrod 3510 extending through the body3502 and slidably movable between retracted and extended positions, anda driving mechanism 3512 for moving the pushrod 3510 between retractedand extended positions. The body 3502 may include a connector 3504complementary to a connector 3029 of the anchor 3012. In the illustratedexample, the body 3502 is provided with a connector 3504 in the form ofscrew threads.

The operation of the insertion instrument 3502 to implant anchor 3012may be better understood with reference to FIG. 77-79. As shown in FIG.77, the anchor 3012 may be coupled to the instrument 3500 using theirmutual connectors 3029, 3504. The pushrod 3510 initially rests againstan end surface of the sleeve 3018 with essentially no load applied. Atensile member 10 passes through the collet 3016, the sleeve 3018, andthe hollow pushrod 3510.

Prior to any swaging operation, the tensile member 10 may be tensionedusing methods described elsewhere herein. Once desired tension has beenestablished, the instrument 3500 is actuated. More specifically, thepushrod 3510 extends outward from the body 3502. This applies acompressive load to the sleeve 3018, causing it to interact with thebody portion 3020, collet 3016, or both in order to swage the collet3016 around the tensile member 10, thus retaining the tensile member 10in-place with the desired amount of tension. As the swage cycle iscompleted, a shoulder 3511 of the pushrod 3510 makes physical contactwith the flange 3032 of the housing 3014.

Will be understood that the extension housing 3021 is mechanicallycoupled to the body 3502 of the instrument 3500. Accordingly, extensionof the pushrod 3510 results in a tensile load being applied to thebreakaway structure 3023 described above. This load is transferredthrough some combination of friction between the sleeve 3018 and/orphysical contact between the shoulder 3511 in the flange 3032. Asdescribed above, the step of swaging is accomplished using a firstpredetermined tensile load.

Once the swaging procedure is completed, the pushrod 3510 is furtheractuated as shown in FIG. 79 to apply a tensile load sufficient tofracture the breakaway structure 3023 and separate the housing bodyportion 3020 from the extension portion 3021. This is accomplished usinga second predetermined tensile force greater than the firstpredetermined tensile load. Once accomplished, the instrument 3500 withthe housing extension portion 3021 still attached may be withdrawn,leaving the anchor 3012 in-place with the tensile member 10 secured withthe desired amount of tension. Any remaining portion of the breakawaystructure 3023 is below flush from the outer surface 3035 of the flange3032. It thus does not protrude to irritate or injure the patient or thesurgeon, and no additional training operation is required.

FIG. 60 illustrates an alternative insertion instrument 2300. Itincludes a stem 2304 extending from the body 2302 and having an anchorconnection mechanism 2308 disposed at a distal end thereof. The stem2304 may be flexible as a result of its material selection.Alternatively, it may incorporate linked segments, corrugations, orsimilar structures to provide flexibility. A hollow pushrod (notvisible), which may be flexible, extends through the interior of thestem 2304 and is slidably movable between retracted and extendedpositions. The hollow pushrod operates like the pushrod 1510 describedabove in order to swage the collet 16 when desired.

Other anchoring devices may be used in conjunction with the variousembodiments of anchors 12 described above in order to implant a tensilemember 10. FIGS. 62-65, 95, and 96 illustrate examples of variousanchoring devices. FIG. 62 illustrates a “button” 1600 to which atensile member may be tied. FIG. 63 illustrates a screw-in suture anchor1602. FIG. 64 illustrates a plate 1605 having a series of openingsformed therein, each of which may receive an anchor. FIG. 65 illustratesa grommet 1606 which has a smooth interior surface to allow a tensilemember to pass freely therethrough. FIG. 95 illustrates another type ofbutton or washer 1608 through which a tensile member may be tied orpassed. The button 1608 includes a U-shaped slot 1611 as well as a hole1613 which can accept a pin or wire to further increase stability andfixation. FIG. 96 illustrates another type of button or washer 1614through which a tensile member may be tied or passed. The washer 1614 isgenerally racetrack-shaped in plan view and includes two opposedU-shaped slots 1616. The portion of the washer 1614 between the 2 slots1616 may incorporate tapered sides giving it a “dog-bone” shape.

The method of applying these principles for implantation and tensioningof a tensile member 10 will now be described in more detail withreference to FIGS. 2 and 66. This particular example illustrates the useof a tensile member 10 to stabilize a human femur. It will be understoodthat this is merely an example, and that the apparatus and methodsdescribed herein may be used to secure and tension a tensile member inany application.

Initially, a tensile member 10 is provided. An appropriate route throughbone “B” or other tissue is determined, and a passage 1700 having firstand second ends 1702, 1704 is drilled in the bone B. The second end 1704of the passage 1700 is prepared to receive the anchor 12, for example bydrilling an appropriately-sized bore 1706 communicating with the passage1700.

A first end 11 of the tensile member 10 is secured in the first end ofthe passage 1700. This may be done using the anchor 12 as describedabove, or some other type of anchor. In the illustrated example, thefirst end 11 of the tensile member is secured to a button 1600 asdescribed above. The tensile member 10 is threaded through the passage1700 so that its second end 13 extends from the second end 1704 of thepassage 1700.

An anchor 12 according to one of the embodiments described above isloaded into the installation instrument 1500 described above or anotherappropriate instrument. The second end 13 of the tensile member 10 isthreaded through the anchor 12 and the installation instrument 1500 andoptionally through the tensioner 1520.

The installation instrument 1500 is then used to seat to the anchor 12into the bore 1706 formed in the bone B. The seating process may includemethods such as simple axial driving, an adhesive bond, threading,screwing into the bone B with small screws through the flange, orcounter-sinking into the bone surface.

With the anchor 12 seated, but the collet 16 not yet swaged, tension maybe applied to the tensile member 10, for example using the tensioner1520 described above. This is referred to as “provisional tensioning”.

The properties of the anchor 12 and the installation instrument 1500enables provisional and permanently stable tensioning of the tensilemember 10, and allows the surgeon to load-cycle and re-tension thetensile member 10 before setting final tension. More specifically, Withthe insertion instrument 1500 abutted against the flange 32 of theanchor 12, tension can be added and removed. The ligament or joint beingrepaired can be load cycled by moving it through some or all of itsrange of motion before setting final tension.

In addition to producing more accurate and repeatable suture tensions,provisional tensioning with a load-setting/load-reading instrument(especially when the suture crosses the axis of a joint, such as amedial collateral ligament (MCL) repair technique) allows the surgeon tovisualize the increase/decrease in tension throughout the joint range ofmotion (max flexion to max extension). This allows the surgeon to ensurethat the tension stays within an acceptable range—and this check is doneafter load cycling the ligament in question to ensure the settle-inperiod is complete.

Once the surgeon is satisfied with the tension established, theinsertion instrument 1500 may be activated. The driving mechanism 1512is used to force the pushrod 1510 towards the actuated position. Thisdrives the sleeve 18 down over the collet 16, thus swaging the collet 16around the second end 13 of the tensile member 10. This swaging actiontakes place with the collet 16 bottomed out at the first end 22 of thehousing 14 of the anchor 12. Accordingly, the act of swaging causeslittle to no change in the tension applied to the tensile member 10.

As the sleeve 18 reaches the fully-actuated position, the sleeveretention features of the housing 14 and the sleeve 18 become mutuallyengaged. FIG. 2 shows an example in which the locking tabs 66 of thehousing 14 engage the annular step 90 of the sleeve 18. This preventsretraction of the sleeve 18 and sets the tensile member 10 permanentlyin position, with the predetermined amount of tension. The tensilemember 10 is thus secured to the bone B with a desired tension.

For any of the anchors and any of the procedures described herein, itmay be desirable to cut off the tensile member 10 so that it does notprotrude beyond the anchor once the swaging operation is completed. Thisavoids injury or irritation to the patient.

FIGS. 88-93 illustrate exemplary cutters which may be used to sever thetensile member 10 at a below-flush location relative to the anchor.

For example, referring to FIG. 88, a cutting instrument 4000 may includea body 4002 with the plurality of collapsible, tapered jaws 4004 whichhave a convex nose 4006. These are shaped so as to protrude into arecess 4008 which may be formed in the housing 14 of the anchor 12, oralternatively in the housing of any of the anchors described herein.

FIG. 89 shows the cutting instrument 4000 in use, where a tensile member10 has been passed through the anchor 12 and secured in place with thecollet 16 and swaged 18. The collapsible jaws 4004 are in an extendedposition in which they slide over the tensile member 10 and allow thenose 4006 to fit into the recess 4008. FIG. 90 shows a cuttinginstrument 4000 being actuated, with the collapsible tapered jaws beingdrawn into the body 4002, thus causing them to collapse inward and severthe tensile member 10. It will be noted that the cutting plane 4010 ofthe jaws 4004 is below flush of an outer surface of the housing 14.

As another example, FIG. 91 illustrates a cutting instrument 4012including a body 4014 with a convex nose 4016. Contained within theconvex nose 4016 is a cylindrical or spherical jaw 4018 having a centralbore 4019 sized to slide over the central member 10. Means (not shown)may be provided for rotating the jaw 4018 relative to the body 4014.

FIG. 91 shows the cutting instrument 4012 in position with the tensilemember 10 passed through the jaw 4018 and the convex nose 4016 receivedin a recess 4008 of an anchor housing 14. FIG. 92 shows the cuttinginstrument 4012 being actuated, with the jaw 4018 being rotated, thuscausing it to sever the tensile member 10. As with the cuttinginstrument 4000, it is noted that the cutting plane 4010 of the jaw 4016is below flush of an outer surface of the house 14.

FIG. 93 shows an exemplary actuation mechanism 4020 similar to theinstrument 1500 described above, comprising a handle 4022 and alever-actuated mechanism 4024 operable to operate the jaws 4004 or 4018described above. The actuation mechanism 4020 may be coupled to thecutting instrument 4000 or 4012 with a neck 4026 which is rigid orflexible.

The procedure described above with reference to FIG. 66 may be performedas a conventional or “open” procedure or in an arthroscopic procedure.FIG. 61 illustrates how the alternative insertion instrument 2300 mayfurther facilitate an arthroscopic procedure. The stem 2304 is shown asbeing flexed in a curved shape so that it can pass through a smallclosed incision “C” in the soft tissue “ST” surrounding the joint. Theother steps in the procedure described above would be identical.

FIG. 69 illustrates an arthroscopic procedure in which a rigid stem isused to position the anchor in the pelvic region, close to thesuperficial surface of the skin. 70 illustrates an arthroscopicprocedure in which a rigid stem is used to position the anchor in thepelvic region, far from the superficial surface of the skin. 70illustrates an arthroscopic procedure in which a rigid stem is used toposition the anchor in the knee region, close to the superficial surfaceof the skin.

As noted above, apparatus and methods described above may be used toimplant tensile members 10 for numerous different types of repairs andprocedures. One specific example where the apparatus and methods areuseful is to implant a tensile member in conjunction with a total kneereplacement (TKR). This is referred to as a tension ligamentaugmentation (TLA) of the knee joint. FIG. 67 shows an example of ahuman knee joint comprising a portion of the “F” articulated with thetibia “T”. The knee joint has implanted therein an artificial joint “J”,the structure of which is outside the scope of the present invention.

A first passage 1800 having first and second ends 1802, 1804 extendsthrough the femur F. A second passage 1900 having first and second ends1902, 1904 extends through the tibia T. The second end 1904 of thesecond passage 1900 is prepared to receive the anchor 12.

A first end 11 of the tensile member 10 is secured in the first end 1802of the first passage 1800 by an anchoring element such as a button 1600.A grommet 1606 is secured in the second end 1804 of the first passage1800, and the tensile member 10 passes through the grommet 1606.

The tensile member 10 further extends around the lateral aspect of theknee joint J down along the upper portion of the tibia T and into thefirst end 1902 of the second passage 1900. The second end 13 of thetensile member 10 extends through the second passage, exiting at thesecond and 1904 of the second passage 1900.

An anchor 12 is described above is implanted in the second in 1902 ofthe second passage 1900. The second end 13 of the tensile member 10extends through the anchor 12. The anchor 12 may be installed, and thetensile member 10 may be tensioned and swaged in place using theinsertion tool 1500 and methods substantially as described above.

One type of repair is a fracture repair. Examples of fracture repairsare shown in FIGS. 97-102.

FIG. 97 illustrates a pelvic brim fracture reduced with tension appliedacross the fracture site by means of a tensile member 10 is, extendingthrough a passage formed in the bone and tensioned as described above,and secured at one end by an anchor (e.g. anchor 12 as described above)and at the other end by a button (e.g. button 1600 as shown in FIG. 62).

FIG. 98 shows a tibial epicondyle fracture reduced with tension appliedtransversely by means of several tensile members 10 extending throughpassages formed in the bone and tensioned as described above. One end ofeach tensile member is secured by an anchor (e.g., anchor 12 asdescribed above), and the opposite ends of the tensile members 10 aresecured to a plate (e.g. plate 1605 shown in FIG. 64).

FIG. 99 shows a fibular fracture reduced longitudinally with a nail andtransversely by means of a tensile member 10 extending through a passageformed in the bone and tensioned as described above. One end of thetensile member 10 is secured by an anchor (e.g., anchor 12 as describedabove), and the opposite end of the tensile member 10 is secured to abutton (e.g., button 1600 as shown in FIG. 62).

FIG. 100 shows a rotator cuff tensioned down against the proximalhumorous by means of a tensile member 10 looped through the rotatorcuff, with its distal ends tensioned as described above and secured byan anchor (e.g., anchor 12 as described above).

FIG. 101 shows a clavicle fracture reduced with tension applied alongthe longitudinal axis by means of a tensile member 10 extending througha passage formed in the bone and tensioned as described above. One endof the tensile member 10 is secured by an anchor (e.g., anchor 12 asdescribed above), and the opposite end of the tensile member 10 issecured to a button (e.g., button 1600 as shown in FIG. 62).

FIG. 102 shows a for moral epicondyle fracture reduced attention appliedtransversely across by means of the tensile member 10 extending througha passage formed in the bone and tensioned as described above. One endof the tensile member 10 is secured by an anchor (e.g., anchor 12 asdescribed above), and the opposite in the tensile member 10 is securedto a button (e.g., button 1600 as shown in FIG. 62).

The apparatus and methods described above herein may further be used forvarious methods for augmenting or replacing natural ligaments. Someexamples of ligament augmentations are described with reference to FIGS.103-110. These augmentations have in common the use of one or moretensile members 10 as described above having a first end anchored to afirst bone, passing through a first passage in the first bone, spanningthe gap to a second bone, spanning a second passage in the second bone,and having a second end anchored to the second bone.

In making these augmentations, the tensile members 10 may be implanted,tensioned, and anchored using any of the apparatus and methods describedabove. In some of the exemplary augmentations, a single tensile member10 is used. This is referred to as a “single-strand” augmentation. Itwill be understood that a single strand of the tensile member may bemade up of smaller individual fibers or sub-strands. In some of theexemplary augmentations, to tensile members 10 are used, where firstends of the two tensile members are anchored at a common first endpoint, and the two tensile members 10 diverge such that their individualsecond ends are anchored at disparate endpoints. This is referred to asa “double-bundle” augmentation.

FIGS. 103A, 103B, and 103C show the human knee joint J having a singlestrand lateral cruciate ligament augmentation. A single tensile member10 has a first end anchored in the tibia T, passes through the tibia Tand the fibula U, spans the gap across the lateral aspect of the tibia Tand femur F, passes through the femur F, and has its second end anchoredin the femur F.

FIGS. 104A, 104B, and 104C show the human knee joint J having a doublebundle lateral cruciate ligament augmentation. A pair of tensile members10 has their common first ends anchored in the tibia T, passes throughthe tibia T and the fibula U, diverge as they span the gap across thelateral aspect of the tibia T and femur F, pass through the femur Fthrough two separate channels, and have their individual second endsanchored in the femur F.

FIGS. 105A, 105B, and 105C show the human knee joint J, having a singlestrand medial cruciate ligament augmentation. A single tensile member 10has a first end anchored in the tibia T, passes through the tibia T,spans the gap across the medial aspect of the tibia T and femur F,passes through the femur F, and has its second end anchored in the femurF.

FIGS. 106A, 106B, and 106C show a human knee joint J, having a doublebundle medial cruciate ligament augmentation. A pair of tensile members10 have their common first ends anchored in the tibia T, pass throughthe tibia T, diverge as they span the gap across the medial aspect ofthe tibia T and femur F, pass through the femur F through two separatechannels, and have their individual second ends anchored in the femur F.

FIGS. 107A, 107B, and 107C show a human knee joint, having a doublebundle anterior cruciate ligament augmentation. A pair of tensilemembers 10 have their common first ends anchored in the tibia T, passthrough the tibia T, diverge as they span the gap between the tibia Tand femur F, pass through the femur F through two separate channels, andhave their individual second ends anchored in the femur F.

FIGS. 108A, 108B, and 108C show a human knee joint, having a doublebundle posterior cruciate ligament augmentation. A pair of tensilemembers 10 have their common first ends anchored in the tibia T, passthrough the tibia T, diverge as they span the gap between the tibia Tand femur F, pass through the femur F through two separate channels, andhave their individual second ends anchored in the femur F.

FIGS. 109A and 109B show a human foot having a double bundle ligamentaugmentation. A pair of tensile members 10 have their common first endsanchored in the tibia T, pass through the tibia T, diverge as they exitthe tibia and wrap around the calcaneus C, pass through the calcaneus Cthrough two separate channels, and have their individual second endsanchored in the calcaneus C.

FIGS. 110A and 110B show a human foot having a double bundle ligamentaugmentation. A single tensile member 10 has its first end anchored inthe calcaneus C, spans the gap between the calcaneus and one of themetatarsals M, passes through the metatarsal M, and has its second endanchored in the metatarsal M.

For any of the ligament augmentations described above, and especiallyfor the augmentations of the ligaments of the knee, it is desirable tocorrectly clock the insertion and origin of the suture passage toreplicate the native stability of healthy knee ligament. For example,FIGS. 111A and 111B are schematic views of the medial aspect of thehuman knee joint, in extension and flexion, respectively, and having adouble-bundle ligament augmentation including first and second tensilemembers 10, 10′. It can be seen that the first tensile member 10 isunder tension when the joint J is an extension, and the second tensilemember 10 prime is under tension when the joint is in flexion. Asanother example, FIGS. 112A and 112B are schematic views of the medialaspect of the human knee joint, in extension and flexion, respectivelyand having a single-strand ligament augmentation. It can be seen thatthe single tensile member 10 is under appropriate tension in bothextension and flexion.

In order to determine accurate locations for drilling the bone passagesto obtain the relationships described above, targets may be establishedon the epicondyle of the femur F or other bone structure. As shown inFIGS. 113 and 114, there would be a target 4050 for flexion augmentationand a target 4052 for an extension augmentation, both referencedrelative to a landmark circle 4054. Location of the targets may beexpressed in Cartesian coordinates or in polar coordinates (R, THETA) asshown in FIG. 114.

The location of the targets may be established and transferred to theepicondyle or other bone by use of a drill guide 4056 as seen in FIGS.115-117. The drill guide 4056 is a solid body having a backside 4058generally conformable to the epicondyle and a front side 4060 providedwith appropriate gradations 4062 such as a Cartesian coordinate grid orpolar coordinate grid. The drill guide 4056 is configured to rotate withthe movement of the knee joint J through various positions from fullflexion to full extension and provides an accurate visual reference of adrill target. The drill guide 4056 may be made of a freely-machine ablematerial such as a biocompatible polymer, allowing the surgeon to drillthrough the drill guide 4056 into the bone.

Another type of repair that may be accommodated using the method andapparatus described herein as a “cerclage” in which a tensile member 10is wrapped around a bone and then placed under tension to form aclosed-loop structure.

FIGS. 118 and 119 illustrate an exemplary clamp 4060 that may be used toreceive and anchor distal ends of a tensile member 10. The clamp 4060has a body 4062 with open ends. Semi-cylindrical outer compressionmembers 4064 are disposed inside the body 4062, flanking an innercompression member 4066. The inner and outer compression members 4066and 4064 are mutually shaped to define two generally cylindricalchannels, each of which receives an end of a tensile member 10. Theinner compression member 4066 has a central slot 4068 which can receivea locking wedge 4070. In use, the ends of the tensile member 10 would beplaced into the channels, the tensile member tensioned as describedelsewhere herein, and then the locking wedge 4070 driven in to swagingcompress the compression members 4064, 4066, thus anchoring the tensilemember 10 and maintaining the desired tension.

FIGS. 120 and 121 illustrate another exemplary clamp 4080 which may beused to receive an anchor distal ends of one or more tensile members 10.The clamp 4080 includes a housing 4082, a collet 4084, and a sleeve4086. The characteristics and configuration of the elements of the clamp4080 may be substantially identical to corresponding elements of theanchor 3012 described above, and the clamp 4080 may be configured as a“breakaway” or “snap-off” device as described elsewhere herein. Theclamp 4080 may include a channel 4088 in the housing 4082 to allowtensile member 10 to lie flat against it. The clamp 4080 may beimplanted using any of the insertion instruments described herein.

FIG. 122 shows a cerclage applied to a human femur F using the clamp4080 of FIGS. 120 and 121 in combination with a tensile member 10. Thetensile member 10 is wrapped around the femur F or other bone, and isdistal ends inserted through the clamp 4080. The methods described aboveare used to tension the tensile member and to force the sleeve 4086 downover the collet 4084 causing it to swage down onto and anchor thetensile member 10.

In the process of performing any of the repairs and/or augmentationsdescribed herein, there is sometimes a need to ream out a passage in theexisting canal of a human bone. During such reaming process, it isdesirable to follow the past of least resistance and to cut away onlysoft bone, leaving the exterior wall undisturbed.

FIGS. 123-126 illustrate a self-tracking reamer 4090 suitable for thispurpose. The reamer 4090 includes a shaft 4092 and a head 4094. Theshaft 4092 is suitably sized and shaped to be received in a manual orpower drill or similar device. The head 4094 includes spiral flutes 4096terminating at a cutting tip 4098 having suitable cutting surfaces 4100.The flutes 4096 may have a single or double lead. The shaft and head aremade of a suitable material such as a stainless steel alloy and havedimensions selected so as to provide some flexibility in bending. Thehead 4094 is configured have a greater diameter in its central portion4102 that at either its proximate end 4104 or the cutting tip 4098. Theoverall shape may be described as a “cobra head” shape.

In use, the reamer 4090 is effective to pull itself into and through thebone canal. Because of the increased diameter at the central portion4102, and the shape of the cutting tip 4098 which principally cuts alongthe centerline, the reamer 4090 is able to bend and follow the path ofleast resistance, cutting only soft bone and not the outer wall. Oncethe reamer 4090 is driven to a desired distance, it can be drivenbackwards (e.g. counter-clockwise) to remove from the bone, or be pulledbackwards with some force while driving clockwise to fully clear thebone canal.

The apparatus and method described herein has numerous benefits comparedto the prior art. It provides a modular device and implant system andmethod that enables provisional and permanently stable tensioning of thetensile member, with minimally-invasive access to and limitedvisualization of the bone surface, using a device that is small andlow-profile to prevent stress-shielding and soft tissue hang-up,implanted by simple and intuitive instrumentation that optimizesworkflow and can be accomplished by one person.

The device and method described above may be used for procedures such astensioning ligaments and tendons, augmenting ligaments and tendons,repairing and/or replacing ligaments and tendons, and reducing andfixate bone fractures.

The foregoing has described apparatus and methods for medical implants.All of the features disclosed in this specification, and/or all of thesteps of any method or process so disclosed, may be combined in anycombination, except combinations where at least some of such featuresand/or steps are mutually exclusive.

Each feature disclosed in this specification may be replaced byalternative features serving the same, equivalent or similar purpose,unless expressly stated otherwise. Thus, unless expressly statedotherwise, each feature disclosed is one example only of a genericseries of equivalent or similar features.

The invention is not restricted to the details of the foregoingembodiment(s). The invention extends, or to any novel one, or any novelcombination, of the steps of any method or process so disclosed.

What is claimed is:
 1. A method for anchoring one or more tensilemembers to bone, comprising: providing an anchor, including: a housingextending along a central axis between open first and second ends, andhaving a hollow interior, the housing including a body portion and anextension portion interconnected by a breakaway structure which isconfigured to retain structural integrity under a first predeterminedtensile load and to separate under a second predetermined tensile loadwhich is greater than the first predetermined tensile load; a colletdisposed in the hollow interior of the body portion, the collet having aperipheral wall defining a central bore for accepting a tensile membertherethrough and an exterior surface, wherein the collet is configuredto be swaged around and against the tensile member; a sleeve having aperipheral wall defining opposed interior and exterior surfaces, thesleeve disposed in the hollow interior of the housing and positionedgenerally axially adjacent to the collet, so as to be movable parallelto the central axis between first and second positions; and wherein atleast one of the exterior surface of the collet and the interior surfaceof the sleeve is tapered and the sleeve and the collet are arranged suchthat movement of the sleeve from the first position to the secondposition will cause the interior surface of the sleeve to bear againstthe exterior surface of the collet, causing the collet to swage radiallyinwards around and against the tensile member; passing one or moretensile members through the central bore of the collet; seating thehousing into a bore formed in the bone; and driving the sleeve from thefirst position towards the second position under the first predeterminedtensile load, so as to swage the collet around the one or more tensilemembers.
 2. The method of claim 1 further comprising applying the secondpredetermined tensile load to the anchor such that the extension portionseparates from the remainder of the housing.
 3. The method of claim 2wherein the breakaway structure separates along a fracture planedisposed below an exterior surface of the body portion.
 4. The method ofclaim 1 further comprising applying tension to the one or more tensilemembers prior to driving the sleeve.
 5. The method of claim 4 whereinthe step of driving the sleeve causes substantially no change in tensionapplied to the one or more tensile members.
 6. The method of claim 1,wherein the housing includes an internal flange disposed at the firstend which prevents axial movement of the collet beyond the secondposition.
 7. The method of claim 6, wherein the collet and the internalflange of the housing are further configured such that axial movement ofthe collet towards the first end of the housing will cause the internalflange to bear against the exterior surface of the collet, causing thecollet to swage radially inwards around and against the one or moretensile members.
 8. The method of claim 7, wherein the housing includesa transition section axially adjacent the internal flange configured toapply a radially inward force against the collet.
 9. The method of claim1, wherein the step of driving the sleeve down over the collet iscarried out using an insertion instrument having an anchor connectionmechanism which engages the housing, and a movable pushrod which engagesthe sleeve.
 10. The method of claim 1 further comprising driving thesleeve until sleeve retention features of the housing and the sleevebecome mutually engaged so as to prevent retraction of the sleeve. 11.The method of claim 10 when the retention features comprisepredetermined dimensions of the sleeve and the housing which permitradial clearance between the sleeve and the housing in the firstposition and which create a radial interference between the sleeve andthe housing in the second position.
 12. A method for anchoring tensilemembers to a joint, comprising: inserting a first tensile member havingfirst and second ends into a first passage having first and second endsin a first bone; securing the first end of the first tensile member inthe first end of the first passage, using a first anchoring element;inserting a second tensile member having first and second ends into asecond passage having first and second ends in the first bone; securingthe first end of the second tensile member in the first end of thesecond passage, using a second anchoring element; passing the secondends of both first and second tensile members through a third passageformed in a second bone; providing a third anchoring element, comprisingan anchor which includes: a housing extending along a central axisbetween open first and second ends, and having a hollow interior; acollet disposed in the hollow interior of the housing, the collet havinga peripheral wall defining a central bore for accepting a tensile membertherethrough and an exterior surface, wherein the collet is configuredto be swaged around and against the tensile members; a sleeve having aperipheral wall defining opposed interior and exterior surfaces, thesleeve disposed in the hollow interior of the housing and positionedgenerally axially adjacent to the collet, so as to be movable parallelto the central axis between first and second positions; and wherein atleast one of the exterior surface of the collet and the interior surfaceof the sleeve is tapered and the sleeve and the collet are arranged suchthat movement of the sleeve from the first position towards the secondposition will cause the interior surface of the sleeve to bear againstthe exterior surface of the collet, causing the collet to swage radiallyinwards around and against the tensile members; passing the second endsof the first and second tensile members through the central bore of thecollet; seating the housing into the second bone; applying a first finaltension to the first tensile member; applying a second final tension tothe second tensile member; and driving the sleeve from the firstposition towards the second position, thus swaging the collet around thesecond ends of the first and second tensile members.
 13. The method ofclaim 12 wherein the swaging causes substantially no change in the firstand second final tensions applied to the first and second tensilemembers.
 14. The method of claim 12 further comprising activating aninsertion instrument to drive the sleeve down over the collet, thusswaging the collet around the second ends of the first and secondtensile members.
 15. The method of claim 12 further comprising, prior tothe step of applying first and second final tensions to the first andsecond tensile members, respectively: applying a first provisionaltension to the first tensile member; applying a second provisionaltension to the second tensile member; evaluating the first and secondprovisional tensions; and increasing or decreasing at least one of thefirst and second provisional tensions.
 16. The method of claim 15wherein the step of evaluating the first and second provisional tensionsincludes moving a ligament or joint being repaired through some or allof its range of motion.
 17. The method of claim 15 wherein the first andsecond final provisional tensions are applied to the first and secondtensile members using a single instrument.
 18. The method of claim 12wherein the first and second anchoring elements are each one of: asuture button, a suture anchor, a bone plate, or an anchor.
 19. Themethod of claim 12 wherein each of the first and second tensile memberscomprise a suture or a surgical cable.
 20. The method of claim 12wherein the first and second final tensions are applied to the first andsecond tensile members using a single instrument.
 21. The method ofclaim 12 wherein the sleeve and the housing each include retentionfeatures, the retention features collectively configured to permitmovement of the sleeve from the first position to the second positionand to mutually engage each other so as to prevent the sleeve frommoving out of the second position.
 22. The method of claim 21 when theretention features comprise predetermined dimensions of the sleeve andthe housing effective to permit radial clearance between the sleeve andthe housing in the first position and to define a radial interferencebetween the sleeve and the housing and the second position.
 23. Themethod of claim 21 wherein the retention elements comprise locking tabsdisposed on one of the housing and the sleeve, and an annular stepdisposed on the other of the housing and of the sleeve.